Trench-excavator.



0. SCALZITTI.

TRENCH EXCAVATOR.

APPucATloN FILED mm2, |916.

1,1 85,8134. y Patented Junel, 1916.

FFICE, l

OLIMPIO SCALZITTI, OF CHICAGO, ILLINOIS.

TRENCH-EXGAVATOR.

specification of Letters Patent.

Patented June 6, 1916.

Application led January 22, 1916. Serial N o. 73,530.

To all whom 'it may concern:

Be it known that I, OLrMrro SCALZITTI, a citizen of the United States, and a resident ofChicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Trench-Excavators, of whichthe following is declared to be a full, clear, and exact description.

This invention relates to excavating machinery, and more particularly to that class of excavating machinery adapted for digging trenches. In digging trenches in sandy or soft soil, there is always danger of the vertical side walls of the trench caving in, and causing serious damage and often injury to persons who might be in the trench.

The primary object of the present invention is to provide trench excavating mechanism of that type employing a boom, around which is driven an endless chain carrying excavating buckets, with supplemental cutting means attached to the boom, for cutting down the side walls of the trench on oblique angles, and said means comprises oblique cutter bars secured to the boom and arranged to cut away the sides of the trench directly after they have been formed by the buckets of the excavating mechanism.

The invention consists in the several novel features hereinafter fully set forth and Y more specifically dened in the claims.

This invention is clearly illustrated in the drawing, accompanying this specification, in which- Figure 1, is a side elevation of the boom, excavator chain and buckets of an ordinary trench excavator, and showing a simple embodiment of the present invention applied to the boom; Fig. 2, is a view partly in plan and partly in horizontal section of the boom and supplemental cutting mechanism, the excavating chain and buckets being omitted therefrom; Fig. 3, is a vertical cross section taken on the line 3 3 of Fig. 1; Fig. 4, is a detail vertical cross section taken on the line 4 4 of Fig. 2; and Fig. 5, is a perspective view of an additional cutter bar.

Referring to said drawing, thereference numeral 10, designates a fragment of the frame of a simple and well-known form of trench excavator, upon which is mounted the usual boom 11, in the well-known and customary manner. Traveling around said boom, in a vertical plane, is an endless chain 12, to which are secured excavating buckets 13, which scoop up the dirt and perform the work of digging the trench; said chain l2 passes around sheaves or pulleys carried by the boom and is driven to move in the direction of the arrow, a, by a suitable motor (not shown), mounted on the excayator frame. It is obvious that with an excavator of the type shown and unprovided with my attachment, a vertical sided trench is dug, the side wall of which are apt to cave in, especially when the trench is dug in sandy or soft soil.

In the simple embodiment of the invention illustrated in the drawings, 14, 14, are two cutter bars which are arranged in the plane of the boom, one on-each side thereof, and they are arranged to extend obliquely with respect thereto as is more clearly seen in Fig. 2. Said cutter bars 14, have portions l5, that extend transversely to the boom and are secured thereto by bolts 16, or otherwise as may be desired. Preferably the transverse members 15, are each made of two pieces lying sido by side and bolted together', each piece being provided with a plurality of bolt holes 17, for the reception of bolts 17a, whereby the angle of inclination of each cutter bar with respect to the boom may be changed to suit the particular trench which is being dug. It is to be understood that the narrow end of the auxiliary cutting mechanism is located near the sheaves or pulleys at the lower extremity of the boom, and said narrower end enters the trench and if desired may extend almost to the bottom thereof. In certain cases, it may-be found desirable to make the sloping out reach the bottom of the trench, and for that reason I have provided extension cutter bars 18 (see Fig. 5) which may be bolted to the lower ends of the cutter bars 14, to provide projecting portions that extend down beyondl the narrow end of the auxiliary cutting mechanism. A plurality of bolt holes in the bars 14, and 18, provide for adjustment of the extension cutter bars. The outer upper ends of the cutter bars 14, are further connected with the boom by diagonal braces 19, which may be in the form of tie rods 20, 21, with turn buckles 22, threaded thereon. The tie rods 20, are secured to lugs or ears 23, fastened to the transverse members 15, of the cutter bars, and the tie rods 21, are secured to a cross bar 24, bolted to the lower side of the boom. If desired, the narrow end of the auxiliary connecting mechanism may also have a tie rod 26, secured to the transverse members 15, and ruiming underneath to the boom. The cutter bars lie in a plane above the upwardly traveling buckets so that the dirt loosened thereby. falls into that part of the trench which is being dug by the buckets.

In operation, the entire excavating mechanism is propelled slowly in the direction of the arrow b, (see Fig. 1,) and the endless chain with the buckets thereon moved in the direction of the arrow a. Said buckets, in the operation of the machine, dig up the soil, as they come in contact with the same, and the boom is gradually lowered until th'e desired depth of the trench is reached, after which the angle of inclination of the boom is maintained constant so as to dig a ditch of even depth. It is to be observed that the buckets dig a vertically sided trench as is usual, but the oblique cutter bars lll, cut through the soil at the upper corners of the vertical walls, forming the trench, and loosen the dirt, which falls down into the trench and after which the ori-coming upwardly traveling buckets gather up the dirt and convey it to the upper end of the boom, where it is discharged into a lateral conveyer (not shown), as is customary and wellknown in excavating machinery of this type. No perceptible amount of additional power is required to operate the auxiliary cutter bars, because the vibration which is present in excavators of this type, is sufficient to agitate the cutter bars to such an extent that the vibration thereof in the sandy or soft soil causes a loosening thereof, and it falls into the portion of the trench which is being dug by the buckets.

More o1' less variation of the exact details of construction is possible without departing from the spirit of this invention, and I desire therefore not to limit myself to the specific form of the invention shown and described but intend in the following claims to point out all of the invention disclosed therein.

I claim as new and desire to secure by Letters Patent.

1. An attachment for trench excavators of the type having a boom and endless chain of excavating buckets, said attachment comprising two cutter bars secured to said boom, there being one on each side of the boom, and extending` obliquely with respect thereto, said cutter bars being arranged to one side of the plane of the upwardly traveling buckets and acting to cut away the upper corners of the trench wall formed by said excavating buckets.

2. In an excavating machine, having a boom and an endless chain of buckets traveling around the same in a vertical plane, an auxiliary sloping wall cutter, comprising two cutter bars, one on each side of the boom, secured'to said boom and extending obliquely with respect thereto, and means for changing the angles of inclination of said cutter bars with respect to the boom.

3. In a trench excavator, having a boom and endless chain of buckets traveling therearound in a vertical plane, an auxiliary sloping side wall cutter comprising two cutter bars, one on each side of the boom and extending at oblique angles with respect to said boom, securing means arranged to vary the angles of inclination of said cutter bars with respect to said boom, and extension cutter bars detachably secured to said main cutter bars.

4. In a trench excavator, having a boom and endless chain of buckets, traveling therearound in a vertical plane, a pair of cutter bars secured to said boom and converging toward each other at their lower ends, there being one cutter bar on each side of the boom, and braces extending back from the upper ends of said cutter bars to said boom.

OLIMPIO SCALZIT'II.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Eatentc, Washington, D. C. 

